Rotary sprinkler

ABSTRACT

A rotary sprinkler having a low-impedance conduit for conveying water to one or more nozzles with minimum loss of energy. A water-motor impeller is positioned outside the conduit and is driven by water bled from the main conduit stream and directed through a reversing jet assembly. One nozzle of the sprinkler has a venturi portion connected through a suction tube to a chamber downstream of the impeller. Water from the downstream side of the motor is aspirated through the suction tube and ejected through the nozzle. The sprinkler is adjustable to rotate continuously, or to cover a selected sector. Nozzles are mounted on interchangeable blocks to permit simple adjustment of the sprinkling pattern. In one form, the sprinkler is a pop-up type arranged to flush dirt and sand from the sprinkler interior each time it is activated.

United States Patent Rosie 1 Apr. 11, 1972 s41 ROTARY SPRINKLER 3,526,363 9/1970 Hauser ..239/206 [72] Inventor: Richard F. Rosie, Dana Point, Calif. Primary Examiner M Henson wood, Jr [73] Assignee: The Leisure Group, Inc., Los Angeles, -MichaelY- Ma C lif Attorney-Jackson & Jones [22] Filed: Dec. 17, 1969 57 ABSTRACT Appl. No.: 885,756

/04 I l ii A rotary sprinkler having a low-impedance conduit for conveying water to one or more nozzles with minimum loss of energy. A water-motor impeller is positioned outside the conduit and is driven by water bled from the main conduit stream and directed through a reversing jet assembly. One nozzle of the sprinkler has a venturi portion connected through a suction tube to a chamber downstream of the impeller. Water from the downstream side of the motor is aspirated through the suction tube and ejected through the nozzle. The sprinkler is adjustable to rotate continuously, or to cover a selected sector. Nozzles are mounted on interchangeable blocks to permit simple adjustment of the sprinkling pattern. In one form, the sprinkler is a pop-up type arranged to flush dirt and sand from the sprinkler interior each time it is activated.

19 Claims, 19 Drawing Figures Patented A ril 11, 1972 3,655,132

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* Sheets-Sheet s Patented A ril 11, 1972 3,655,132

7 Sheets-Sheet 6 ROTARY SPRINKLER BACKGROUND OF THE INVENTION Rotary water sprinklers have long been used for both home lawn sprinkling and in large-scale watering of golf courses, cemeteries, and other expanses of turf. Rotary sprinklers are also used commercially in agricultural irrigation. A nozzlecarrying head of the sprinkler is typically rotated by an impulse drive, or by a water motor having an impeller driven by water and coupled to the head through a train of speed-reducing gears. Various kinds of mechanisms have been used to provide variable-sector or part-circle rotation of the nozzle head, and it is also known to mount the head to be vertically movable so it is flush with the ground when not in use. The latter feature characterizes a pop-up sprinkler in which the head is moved above the ground by water pressure when the water is turned on.

While these known rotary sprinklers are effective in many respects, they are also typically inefficient, and may require a high-pressure water source and a high trajectory of the sprinkler output stream to cover even moderate distances. A highly arched stream is undesirable because wind interferes with the stream and produces an uneven sprinkling pattern in the area being watered. A major cause of this problem is placement of the water-motor impeller or rotor and other components in the conduit which conveys water from a main water line to the nozzle. The parts-clogged conduit presents a high impedance to the flowing stream and substantially reduces stream velocity such that high nozzle trajectories become necessary, or high water pressures are required.

Known rotary sprinklers are also typically complex and difficult to clean and maintain, and often must be completely replaced when a different gallonage or stream range is made necessary by a change of planting in the area being watered. Variable-sector adjustments are sometimes unreliable and difficult to perform, and may not provide a sufficient adjustment range to cover a broad range of irrigation requirements. Known units are also often constructed of materials which are susceptible to chemical attack by fertilizers and insecticides, or by the water itself.

The rotary sprinkler of this invention solves these problems, and is a highly efficient and flexible unit which is simple to install, adjust and maintain, and is useful in a wide variety of watering applications. The sprinkler has a head which is rotatably mounted in a housing having an inlet adapted for connection to a water line. A tubular riser pipe or conduit extends downwardly from the center of the head to receive water flowing through the inlet. A water motor for driving the head is located wholly outside of the obstruction-free conduit, and water accordingly flows smoothly and at high velocity directly to one or more nozzles in the head. Low-energy water on the downstream side of the motor is aspirated out of the sprinkler by one of the nozzles which includes a vacuum venmm.

The sprinkler head can be mounted without a housing to be vertically stationary, or can be of the housed pop-up type to present a ground-level profile when not in use. The pop-up configuration is self-flushing each time the sprinkler is used, and any accumulations of dirt, grass or other particles are removed automatically. The head can rotate continuously in one direction, or is easily adjusted for part-circle operation over any desired sector. Nozzles are interchangeable so the same basic sprinkler can be quickly adapted for use in many different applications. The sprinkler is constructed of materials which are substantially inert in the presence of chemicals in the feed water or applied to the surrounding soil.

SUMMARY OF THE INVENTION Briefly stated, the invention relates to a rotary sprinkler having a hollow housing with a water inlet. A nozzle assembly is rotatably supported by the housing, and has a sprinkling nozzle and a conduit for conveying water from the inlet to the nozzle. A water motor having a rotatable impeller is connected between the housing and nozzle assembly to rotate the nozzle. The impeller and related components of the water motor are located entirely outside the conduit so water passes to the nozzle from the water supply through an unobstructed low-impedance tube or pipe.

Preferably, water to drive the water-motor impeller is bled through a port in the conduit, and is then aspirated out of the sprinkler after it has passed through the motor. The nozzle assembly preferably includes a vacuum nozzle for removing water downstream of the motor, and further includes a removable nozzle block having a plurality of nozzles in fluid communication with the conduit. The water motor preferably includes a direction-control means such as a pair of jets arranged for bi-directional operation of the impeller, and a switching means for controlling the jets to determine the direction and extent of nozzle rotation. In one form, the sprinkler is of a pop-up type, and is arranged to be self-flushing to remove sand or dirt from the housing each time it is operated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a pop-up rotary sprinkler with a rotatable nozzle head shown in an elevated position;

FIG. 2 is a top view of the sprinkler shown in FIG. 1;

FIG. 3 is an exploded perspective view of the components of the pop-up rotary sprinkler;

FIG. 4 is a sectional elevation, partly broken away and taken on line 44 of FIG. 1;

FIG. 5 is a top view of the sprinkler with a top cap removed to show portions of the sprinkler interior;

FIG. 6 is a section on line 6-6 of FIG. 4;

FIG. 7 is a top view of a water motor for the sprinkler, the motor being shown without its top plate;

FIG. 8 is an unfolded sectional view of the motor taken on line 8-8 of FIG. 7;

FIG. 9 is an elevation of a jet-switching assembly for the motor;

FIG. 10 is a section on line 10-10 of FIG. 9;

FIG. 11 is a sectional elevation of an adjusting ring assembly;

FIG. 12 is a bottom view of the adjusting ring shown in FIG. 1 1;

FIG. 13 is a sectional elevation of a vacuum nozzle used in the sprinkler;

FIG. 14 is a sectional elevation of a nozzle block housing;

FIG. 15 is a sectional plan view of a nozzle block and vacuum nozzle;

FIG. 16 is a view on line 16-l6 of FIG. 14;

FIG. 17 is a view on line 1717 ofFIG. 15;

FIG. 18 is a side elevation of another form of the invention; and

FIG. 19 is a sectional elevation of a lower portion of the sprinkler shown in FIG. 18.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-6, a rotary sprinkler 10 according to the invention includes a stationary outer housing 11, and a sprinkler head 12 positioned within the outer housing. The sprinkler head has a rotatable nozzle assembly 13 and a nonrotating mounting shell or inner housing 14 which supports the noule assembly within outer housing 11. The mounting shell is vertically movable within the outer housing if the sprinkler is arranged as a pop-up unit, but may be stationary if the retracting feature of the sprinkler head is not needed.

Stationary outer housing 11 has a hollow and generally cylindrical body or outer shell 15, the upper end of which flares outwardly to define a top flange 16. An annular shoulder 17 is formed in the upper surface of flange 16, and a top plate 18 with a central opening. 18a seats against the shoulder. The top plate is secured to flange 16 by screws 19 threaded into bosses 19a on the flange. Three tabs or stop members 20 (FIGS. 3-5) are evenly spaced apart around the inner periphery of top plate 18 and extend downwardly therefrom to project slightly inwardly from the inner surface of outer shell 15. An annular shoulder 21 is formed in the upper surface of the top plate around central opening 18a.

The bottom of outer shell tapers inwardly to a horizontal floor 22 with a central opening 22a (FIG. 4). An externally threaded hollow extension 23 projects downwardly from floor 22, and a supply-line coupler 24 is threaded on the extension. The coupler is hollow and has internal threads 24a at its lower end to mate with a corresponding fitting (not shown) on a water-supply conduit. The coupler has an inwardly extending annular flange 25 just above threads 24a.

A short annular wall 26 extends upwardly from floor 22 of the outer shell slightly radially outwardly of central opening 22a. an annular rib 27 extends downwardly from the undersurface of floor 22 immediately below wall 26. Four short tabs or guide lugs 28 (FIGS. 4 and 6) extend inwardly from floor 22 into opening 220.

A hole 29 extends through the lower part of outer shell 15 to drain the shell when the sprinkler is not in use. A plurality of vertically extending decorative stiffening ribs 30 are formed on the outer surface of shell 15, and one rib 30a is shaped as a pointer to designate one limit of rotational travel of the sprinkler head when the sprinkler is set to reciprocate to a sector less than 360. The inner surface of the shell has a plurality of vertically extending guide ribs 31 and a single guide slot 32 (FIGS. 3 and 5).

Inner housing 14 (FIGS. 3-5) includes a cup-shaped motor housing 33 having a base 34 with a central opening 35. A bushing 35a is fitted in opening 35 to seat against the undersurface of base 34. A rotation-control screw 36 is threaded vertically through base 34, and an annular channel 37 is formed in the upper surface of the base between the screw and central opening 35. A generally cylindrical sidewall 38 extends upwardly from base 34, and has an internal ring gear 39 spaced slightly below its upper end.

A keyway 40 extends upwardly from ring gear 39 in the inner surface of sidewall 38, and a plurality of outwardly extending ribs 41 are formed in the outer surface of the sidewall. When inner housing 14 is positioned within stationary outer housing 11 as shown in FIGS. 4 and 5, ribs 41 mate with guide ribs 31 on outer shell 15 to prevent rotation of the motor housing with respect to the outer housing. One rib 41a extends radially beyond the rest of ribs 41, and fits into guide slot 32 on the outer shell so the inner housing can only be installed in the outer housing in a predetermined position.

Inner housing 14 also includes an adjusting ring assembly 45 (FIGS. 3, 4, l1 and 12) having a cylindrical sleeve 46. The lower end of the sleeve fits snugly within the upper end of sidewall 38 of motor housing 33 against the top of ring gear 39. A key 47 extends radially from the cylindrical sleeve and mates with keyway 40 to prevent rotation of the sleeve within the motor housing. Three inwardly extending support legs 48 are spaced 120 apart on the inner surface of the cylindrical sleeve between its upper and lower ends, and each support leg has a raised button or detent 49 on its upper surface. Three spring-retaining legs 50 also extend inwardly from the inner surface of the cylindrical sleeve, and these legs are spaced 120 apart and are positioned below the top of the sleeve and above a horizontal plane in which support legs 48 are disposed.

Adjusting ring assembly 45 has a sector-setting ring 53 having at its lower end an outwardly extending annular flange 54. The bottom surface of the annular flange defines a plurality of closely spaced radially extending shallow teeth or ribs 55. Three wire spring clips 56 are captively positioned between legs 50 on sleeve 46 and the upper surface of flange 54 to urge the sector-setting ring resiliently against support legs 48 on the sleeve. Ribs 55 on the bottom of flange 54 engage detents 49 on the support legs, and a moderate force is required to rotate the ring with respect to sleeve 46 as the ribs ride over detents 49in click-stop fashion.

A reversing cam 57 (FIG. 12) is integrally formed with sector-setting ring 53, and extends below the ribbed bottom surface of flange 54. The cam is spaced inwardly from the periphery of the sector-setting ring to clear support legs 48 of cylindrical sleeve 46 when the ring is rotated with respect to the sleeve. A plurality of circular sockets 58 extend downwardly from the top surface of ring 53, and are uniformly spaced apart approximately 10 around the ring.

Rotatable nozzle assembly 13, the other major component of the sprinkler head 12, includes a nozzle subassembly 63 having a nozzle-block housing 64 (FIGS. 3-5, l4, 16). This housing has a horizontal circular base 65 with a horizontal annular groove to receive an O-ring seal 66. The base extends radially outwardly just above seal 66 to define an annular shoulder 67. A sidewall 69 in the form of a partial cylinder extends upwardly from the top of shoulder 67, and a vertical transverse wall 70 extends between the upper ends of sidewall 69.

The lower edge of transverse wall 70 is spaced above base 65, and a chamber wall 71'- slopes downwardly and rearwardly away from the bottom of the transverse wall to join the top of base 65. A pair of stiffening walls 72 extend rearwardly from transverse wall 70 to sidewall 69, and downwardly to the upper surfaces of chamber wall 71 and base 65. A bridging wall 73 extends between the stiffening walls, and these three walls are shaped to define a cap-retaining socket 74 having a captive retaining screw 75 horizontally threaded therethrough. A notch 76 is cut in the upper end of sidewall 69 to provide access to a socket head on retaining screw 75.

A hollow boss 79 extends upwardly from the top of circular base 65 below access notch 76 and between walls 72. A sector-adjusting plunger or pin 80 is fitted within boss 79, and is held captively in place by a retainer 81 secured in the upper end of the boss. The lower end of pin 80 extends into a hole formed through base 65 at the bottom of boss 79, and the upper end of the pin extends above the retainer 81 and boss so it can be depressed by a finger inserted between stiffening walls 72. A spring 82 is fitted within the boss between the top of base 65 and an annular rib 83 on adjusting pin 80, and the spring urges the pin upwardly against retainer 81 so the lower end of the pin normally does not extend below the bottom of base 65.

A hollow riser pipe or inlet tube 84 extends downwardly from the center of circular base 65 of the nozzle-block housing. The interior of tube 84 defines a smooth and unobstructed water conduit 85 from the lower end of the tube through circular base 65. An upper annular flange 86 extends radially outwardly from the surface of tube 84 and is spaced below the undersurface of base 65.

A segmented lower annular flange 87 extends radially outwardly from the inlet tube between flange 86 and the bottom of the tube, and one portion of flange 87 is radially elongated to define a key 87a. Four vertically spaced-apart O-ring seals 88 are seated in annular grooves in the inlet tube between flange 87 and the bottom of the tube. A water-motor inlet slot or port 89 (FIG. 16) is cut through the side of the inlet tube midway between the two uppermost O-ring seals, and the port extends into communication with conduit 85.

In areas where the supply water is sandy or laden with other particulate mater, a filter 90 (FIG. 13) is preferably inserted in the lower end of inlet tube 84. Filter 90 has a hollow cylindrical body 90a which makes a snug press fit in conduit 85 of the inlet tube, and an outwardly extending flange 90b at the bottom of the body abuts the end of the inlet tube to position the filter properly. The filter body is apertured to form a screen which blocks passage of particulate matter into the water motor through water-motor inlet port 89.

A suction tube 91 (FIGS. 3 and 16) extends radially outwardly from one side of inlet tube 84. The upper end of the suction tube merges into the bottom surface of base 65, and the lower end of the tube terminates adjacent lower annular flange 87 just above upper O-ring seal 88. The interior of the tube is hollow to define a suction channel 92 extending up wardly through circular base 65. The upper end of suction channel 92 opens into a threaded opening 93 (FIG. 3) in an upwardly inclined boss 94 integrally formed on the forward face of chamberwall 71 at one side of the upper end of conduit 85. With the exception of retaining screw 75, sector-adjusting pin 80, retainer 81 and spring 82, nozzle-block housing 64 is preferably integrally molded from a single piece of material.

A suction nozzle 97 (FIGS. 3, 4, 13, and 17) is threaded at its rear end to be received in threaded opening 93 of boss 94. The suction nozzle has a stepped internal bore defining an outlet bore 98 and a plug-receiving bore 99 extending rearwardly from the outlet bore and separated therefrom by an annular shoulder 100. A plug 101 fits snugly within bore 99 to be rigidly secured in the bore, and has a forward end which is spaced slightly rearwardly of shoulder 100. The top of the plug is flattened, and the rear part of the top surface of the plug is chamfered to define a continuous suction passage 102 extending from the top of suction channel 92 to outlet bore 98.

A longitudinal bore 103 extends rearwardly from the front end of the plug part way along its length, and a lateral bore 104 extends completely through both the suction nozzle and the plug into communication with the rear end of longitudinal bore 103. This assembly acts as an aspirating jet, and water flowing into lateral bore 104 and through longitudinal bore 103 into outlet bore 98 produces a reduced pressure in suction passage 102. An O-ring seal 105 is seated in an annular groove in the suction nozzle just behind the front end of the nozzle.

A nozzle block 108 (FIGS. 3, 4, l4 and 15) is integrally formed, and includes a base 109. The base has a shoulder 110 extending around its periphery. Three conical turrets extend from the front face of the base to define a long-range nozzle 111, short-range nozzle 112 and intermediate-range nozzle 113. The inner bores of nozzles 111 and 112 are contoured to match the range and gallonage requirements of a particular sprinkling application. The interior of intermediate-range nozzle 113 is shaped to receive suction nozzle 97, with O-ring seal 105 making a snug fit against the interior of nozzle 113.

Nozzle block 108 is removably fitted (FIGS. 4 and 14) in nozzle-block housing 64, with base 109 seating against a shoulder 115 formed in chamber wall 71. An O-ring seal 116 is positioned between shoulder 115 of the housing and shoulder 110 of the nozzle block to prevent water leakage between these components. The rear face of nozzle-block base 109, chamber wall 71, and the top of circular base 65 define a chamber 117 at the upper end of inlet-tube conduit 85, and water flowing upwardly through this conduit accordingly flows without obstruction through nozzles 111 and 112, and into lateral bore 104 of the suction nozzle to be ejected from the outlet bore of this nozzle.

The nozzle block is held securely in place in the housing by a pair of retaining pins 118 which are fitted through holes 119 in chamber wall 71 to extend into sockets 120 in the top of circular base 65. The retaining pins seat in grooves 121 formed in the front surface of base 109 of the nozzle block, and the nozzle block is thereby securely held in place with O-ring seal 116 compressed to provide leak-free operation.

The nozzle block is intended to be an interchangeable component, and other blocks having different nozzle configurations are quickly substituted to vary the gallonage or range characteristics of the rotary sprinkler. In low-gallonage applications involving say less than five gallons per minute, the long and short range nozzles may be entirely omitted, and the nozzle block is provided with only a single intermediate-range nozzle which fits over the suction nozzle. Various nozzle blocks can thus be provided with the basic rotary sprinkler to provide one, two, three or more nozzles as necessary for a particular watering application.

Nozzle assembly 63 is completed by a circular cap 124 (FIGS. l-4) having a short retaining post 125 extending downwardly from the center thereof to fit into cap-retaining socket 74 of the nozzle-block housing. The retaining post has an annulargroove 126 therearound, and retaining screw 75 is seated in the groove to secure the cap to the top of the nozzleblock housing. In the pop-up configuration shown in the drawings, cap 124 seats against shoulder 21 of top plate 18 when the sprinkler is not in use and the nozzle subassembly is retracted.

A motor subassembly 130 (FIGS. 3, 4, 7-10) is the second major component of rotatable sprinkler head 12. This subassembly includes a circular base 131 having a central circular opening so the base can be fitted snugly over the lower end of inlet tube 84 of the nozzle-block housing. When the motor subassembly is thus installed on the inlet tube, the upper surface of the base abuts segmented lower annular flange 87, and key 87a seats between a pair of short posts 132 which extend upwardly from the top of the base to position the motor subassembly with respect to water-motor inlet port 89. A recess or notch 133 is formed in the top of base 131 to form a clearance space immediately below the bottom of suction tube 91 and the inlet of suction channel 92.

A circular apron 135 (FIGS. 4 and 9) extends downwardly from the lower periphery of base 131, and an annular flange 136 is spaced inwardly from apron 135 and extends downwardly from the undersurface of the motor base around the central circular opening through the base. A bridging block 137 (FIG. 4) is integrally formed between one side of flange 136 and apron 135, and the block extends upwardly against the undersurface of base 131. A shallow jet-post hole 138 extends downwardly from the top surface of base 131 above block 137, and a laterally extending water-inlet hole 139 is formed through flange 136 and block 137 into communication with hole 138. Hole 139 is positioned to receive water from inlet port 89 in inlet tube 84.

The motor subassembly also includes a generally circular top plate 142 having a central opening 143 with a radially extending notch 144 which provides clearance for suction tube 91 when the motor subassembly is installed on the nozzleblock housing. Central opening 143 is dimensioned to fit snugly over upper annular flange 86 on the inlet tube.

A plurality of gear-shaft bosses 146 extend downwardly from the undersurface of top plate 142, and are spaced around the periphery of the top plate. A corresponding plurality of gear-shaft bosses 147 extend upwardly around the top surface of circular base 131'. Extending between the pairs of bosses on the circular base and top plate are gear shafts 148. These shafts are pressed into the bosses, and they secure the top plate and circular base together. Several of the shafts extend through the top plate, and are anchored in place by retaining clips 149.

A plurality of spur gears a, b, 0, etc., are mounted on shafts 148 (FIGS. 7 and 8) and these gears define a reduction gear train with a high-speed input gear 150a and a low-speed output gear 150r. With the exception of the input and output gears, each shaft carries two gears which are integrally formed to rotate together. The reduction gear train is arranged around the periphery of the motor subassembly to partially encircle inlet tube 84. When the rotary sprinkler is assembled, output gear 150r meshes with internal ring gear 39 on motor housing 33. A water-wheel impeller 151 is integrally formed on input gear 150a, and is spaced slightly below the teeth of the input gear.

A generally cylindrical jet post 154 (FIGS. 3, 7-10) is slightly reduced in diameter at its lower end to make a press fit into shallow hole 138 in circular base 131 of the motor subassembly. The jet post has a blind hole 155 extending from the lower end thereof upwardly part way along its length. A pair of jets 156 and 157 are formed laterally through the side of jet post 154 into communication with the upper end of blind hole 155. The jets are vertically positioned to be level with the horizontal centerline of the impeller, and are angularly spaced apart (approximately 54 in the configuration shown in the drawings) to aim at opposite sides of the shaft which carries impeller 151. A radially extending key 158 (FIG. 10) projects from the side of jet post 154 opposite jets 156 and 157. The top of the jet post has a socket to receive a shaft 159 which extends upwardly through top plate 142 to be anchored by one of retaining clips 149.

A hollow, generally cylindrical jet baffle 162 makes a loose slip fit over jet post 154. One side of the bafile is enlarged to define a curved internal slot 163 (FIG. 10) which receives key 158 of the jet post. The key limits the extent of rotational travel of the baffle on the post to the positions defined by the ends of slot 163.

An L-shaped spring-retaining arm 164 extends radially outwardly and upwardly from the upper side surface of jet baffle 162 approximately opposite curved slot 163. A jet-control slot 165 is cut through the sidewall of baffle 162 below springretaining arm 164. Slot 165 is dimensioned so jet 156 is covered and jet 157 is uncovered when the baffle is rotated to position key 158 against one end of curved slot 163. When the baffle is rotated to place the key against the other end of the curved slot, jet 156 is covered by the inner surface of the baffle, and jet 157 is open as it faces jet-control slot 165.

A jet-switch member 169 has a hollow cylindrical body 170 fitted on shaft 159 between top plate 142 and the top of jet baffle 162. A washer 171 is inserted on shaft 159 between the jet bafile and body 170 so these components can rotate freely with respect to each other on the shaft. A short spring-retaining arm 172 extends radially from a lower side surface of body 170, and a wire switching spring 173 has its ends secured in spring-retaining arms 164 and 172 respectively.

An upper switching arm 174 extends radially outwardly and then upwardly from the upper side surface of body 170 of the jet-switch member. The upwardly extending portion of the upper switching arm is positioned in a slot 175 in top plate 142 of the motor subassembly. A tab 176 extends upwardly from the top of the upper switching arm above the level of the top surface of top plate 142. When the rotary sprinkler is assembled, tab 176 is positioned for actuation by reversing cam 57 of adjusting ring assembly 45 as explained in detail below.

An L-shaped lower switching arm 178 extends first radially outwardly and then downwardly from the lower side surface of body 170 of the jet-switch member. The lower switching arm extends downwardly below the level of the top surface of circular base 131 of the motor subassembly. When the rotary sprinkler is assembled, the lower switching arm is positioned for actuation by rotation-control screw 36 in motor housing Jet post 154, baffle 162, and switch member 169 form a direction-control switch for the rotary sprinkler, and these components control the direction of rotation of impeller 151 when water is flowing through the rotary sprinkler. Wire switching spring 173 is designed to make the switching assembly bi-stable so one of jets 156 and 157 is always covered while the other jet is uncovered, and only one jet sees" the impeller at a time. The spring gives the switch a snap action and forces jet baffle 162 into one of the two limiting positions defined by curved slot 163 and key 158 to prevent jet-control slot 165 from being stably positioned at any location intermediate jets 156 and 157.

A tubular guide bushing 180 (FIGS. 3, 4 and 6) makes a slip fit over the lower end of inlet tube 84 and lowermost O-ring seal 88. Bushing 180 extends downwardly through central opening 22a between guide lugs 28 on the floor of outer shell 15, and the bushing has an outwardly extending flange 181 at its lower end. A gasket 182 is seated on the top of flange 181, and is sealed against annular rib 27 of outer shell when the sprinkler is operating. Bushing 180 moves downwardly when the water supply is turned off, and flange 181 rests on flange of coupler 24 when the sprinkler is not in use.

To assemble the rotary sprinkler, adjusting ring assembly 45 is first slipped upwardly over inlet tube 84 of nozzle-block housing 64 so the upper end of cylindrical sleeve 46 fits over O-ring seal 66 adjacent annular shoulder 67 of circular base 65. The nozzle-block housing rotates with respect to the adjusting ring assembly when the rotary sprinkler is in operation, and water leakage between these components is prevented by seal 66. Motor subassembly 130 is then moved upwardly over inlet tube 84with suction tube 91 fitting through notch 144 of top plate 142.

The motor subassembly is properly positioned on inlet tube 84 when the undersurface of segmented lower annular flange 87 abuts the top of circular base 131 and key 87a is seated between posts 132. In this position, water-motor inlet port 89 in the inlet tube is aligned with water-inlet hole 139 in the motor subassembly, and O-ring seals 88 prevent water leakage between these parts. When the rotary sprinkler is in operation, motor subassembly rotates with nozzle-block housing 64 as these components are rotationally clamped together by posts 132 and key 87a.

Motor housing 33 is then installed on the nozzle-block housing by moving the housing upwardly over inlet tube 84 to the position shown in FIG. 4. In this position, motor output gear r is meshed with internal ring gear 39 of the motor housing. The upper end of sidewall 38 of the motor housing fits snugly over the lower end of cylindrical sleeve 46 of the adjusting ring assembly with key 47 seated in keyway 40 of sidewall 38. The motor housing and adjusting ring assembly are thus secured together as a unit, with keyway 40 and key 47 preventing any relative rotation therebetween.

A washer 185 (FIG. 4) is next slipped over inlet tube 84 against the flanged undersurface of bushing 35a, and a C- shaped clamp ring 186 is fitted into an annular groove adjacent the lower end of the inlet tube just below the washer. Inner housing 14, which includes the motor housing and adjusting ring assembly, is now securely clamped in place on the nozzle-block housing by ring 186, with washer 185 and bushing 35a preventing binding as the nozzle-block housing rotates with respect to the inner housing. Nozzle block 108 is then fitted in place over suction nozzle 97 if this step has not already been taken care of in assembly of nozzle subassembly 63, and the noule block is locked in place with retaining pins 1 18.

The assembled rotatable sprinkler head 12 is now inserted in outer shell 15 with rib 41a aligned in guide slot 32 (FIG. 5). Ribs 41 on the motor housing fit between corresponding guide ribs 31 on the inner surface of the outer shell. Rotation of the inner housing with respect to the outer shell is thus prevented, and the ribs cooperate to guide the sprinkler head as it is moved vertically within the outer shell.

Guide bushing is installed through central opening 22a of the outer shell and is held captive when coupler 24 is installed. The upper end of the guide bushing fits over the lower end of inlet tube 84 and lower O-ring seal 88. Top plate 18 is then secured by screws 19 on the top of the outer shell, and assembly is completed by installing cap 124 on the nozzle-block housing with retaining post 125 being locked in place by retaining screw 75.

The assembled rotary sprinkler is then coupled to a water conduit (not shown) by threading coupler 24 onto a mating fitting of the conduit. When the water is turned off, sprinkler head 12 is in a retracted position (shown in phantom in FIG. 4) with cap 124 seated on shoulder 21 of the top plate and bushing 180 resting on flange 25 of the coupler. In a normal installation, the top plate is positioned approximately flush with the surrounding ground, and the cap is also flush with the ground so lawn mowers or vehicles can pass thereover.

When the water supply to the sprinkler is turned on, water flows through coupler 24, guide bushing 180 and inlet tube 84, and the flowing water forces the sprinkler head to rise within the stationary outer housing until the top surface of sidewall 38 of motor housing 33 abuts the bottom of stop member 20 as shown in FIG. 4. After the inner assembly has popped up into this fully extended position, lower O-ring seal 88 and gasket 182 seal the inside of outer housing 11 from the water supply so water can only flow upwardly within the unit through inlet tube 84 and associated guide bushing 180.

As the sprinkler head and guide bushing move between the retracted and extended positions, water flows upwardly around the outside of guide-bushing flange 181 and between guide lugs 28 into the interior of the outer housing and around the sprinkler head. The flushing water passes out of the sprinkler between stop members 20 and flows onto the surrounding ground. This momentary water flow flushes any sand or debris that may have accumulated within the sprinkler, and the flowterminates when the guide bushing is fully elevated to seat gasket 182 on rib 27.

A similar flushing action occurs when the main water supply is turned off and the sprinkler head descends by its own weight to the retracted position, forcing part of any remaining water in the outer shell out of the unit. Dirt and sand are thus prevented from accumulating within the sprinkler as a result of this self-flushing action which occurs twice during each operating cycle of the sprinkler. The outside of the sprinkler head is isolated from the water pressure of the main supply conduit once the head is fully elevated, and any transient highpressure water pulses from the conduit cannot react on the outer surface of the head with heavy forces which might break top plate 18 and expel the head from the stationary housing.

When the water supply to the sprinkler is turned on and the rotatable sprinkler head has popped up to its fully extended position, water flows upwardly through inlet tube 84 without obstruction and emits from nozzles 111, 112 and 113. Due to the pressure differential between the lower end of inlet tube 84 and the nozzle block, water is also forced through watermotor inlet port 89 in the inlet tube to flow through waterinlet hole 139 in the motor subassembly base and upwardly through jet post 154 to emit from whichever of jets 156 and 157 is uncovered by jet baffie 162. Water flowing through the jet strikes the impeller and rotates it at high speed, and the impeller in turn drives gears 150 in the water-motor gear train to rotate output gear 150r along internal ring gear 39 of the motor housing.

In the configuration illustrated in the drawings, the impeller rotates at approximately 12,000 rpm at a water inlet pressure of 40 psi. When a 0.058 inch jet is used to drive the impeller, approximately 40 inch pounds of torque are delivered by the water motor. The gear train illustrated in the drawings provides a speed reduction of 3,881 to 1, giving a nozzle-block rotation speed of about 3 rpm. The impeller rotational speed can be varied by changing the size of the jets, or by reorienting the jets to vary the angle at which the water stream strikes the impeller.

Low-energy water on the downstream side of the impeller pools in the chamber defined by the bottom of motor housing 33, and is aspirated out of the sprinkler interior through suction channel 92 in suction tube 91. Pressure in the suction tube is reduced immediately upon the beginning of water flow through vacuum suction nozzle 97, and this nozzle is designed to be capable of evacuating several times the volume of water out of the motor housing which actually flows through the jets to rotate the water-motor impeller. The spent water on the downstream side of the impeller is thus immediately aspirated out of the water motor, and the impeller is free to rotate at high speeds without back pressure from the low-energy water. The aspirated water is ejected from the suction nozzle along with the main stream which emits from intennediate-range nozzle 113 of the nozzle block.

A major feature of this nozzle rotating system is that the motor impeller is positioned outside the main stream of water being fed to the nozzles. Inlet tube 84 is thus free of obstruction, and water emits from the nozzles at high velocity. For example, the sprinkler illustrated in the drawings uses nozzles which are elevated only about 22.5 above the horizontal, providing a low-trajectory stream which minimizes wind interference and distortion on the spray pattern. The efiiciency of the sprinkler also permits it to be used with low-pressure water systems.

With the water motor in operation as described above, rotation of output gear 150r forces nozzle subassembly 63 and motor subassembly 130 to rotate with respect to the stationary outer housing. Inner housing 14 is confined against rotation by ribs 31, 41 and 41a, and by guide slot 32, and the output gear walks around internal ring gear 39 of the motor housing to rotate nozzle assembly 13. When the rotary sprinkler is set for part-circle reversing operation as shown in the drawings,

switch member 169 rotates back and forth between rotationcontrol screw 36 (a fixed stop) and reversing cam 57 (a variable-position stop).

When jet bafile 162 is positioned to open jet 156 as shown in FIGS. 9 and 10, the impeller rotates clockwise as viewed from the top, and the motor subassembly and nozzle assembly also rotate clockwise. As the sprinkler rotates in a clockwise direction, lower switching arm 178 is moving toward the fixed stop defined by rotation-control screw 36 in the lower part of the motor housing. Continued rotation brings the lower switching arm into contact with this screw, and forces a counterclockwise rotation of switch member 169 which acts upon switching spring 173 to cause a reverse or clockwise rotation of the jet baffle to the position shown in phantom in FIG. 10 (this figure is a bottom sectional view, and rotational directions are accordingly reversed from the top-view directions used in this text). Jet 156 is then blocked and jet 157 is opened to drive the impeller in a counterclockwise direction, and the rotation of the sprinkler is thereby reversed.

As the sprinkler rotates counterclockwise, tab 176 of upper switching arm 174 eventually comes into contact with the variable-position stop defined by reversing cam 57 on the underside of sector-setting ring 53. Continued rotation forces tab 176 to ride along the surface of the reversing cam, and switch member 169 rotates clockwise until it is snapped into the other of its two stable positions by over-center switching spring 173. The switch member is then back in the position shown in solid line in FIG. 10, and jet baffle 162 (which moves in a direction opposite to the direction of rotation of the switch member) rotates counterclockwise to expose jet 156 which drives the impeller in a clockwise direction. The rotation of output gear 150r is accordingly reversed, and the motor and nozzle assemblies resume clockwise rotation. This cycling or reciprocating operation will continue as long as water flows through the sprinkler.

The angular sector over which the sprinkler operates is determined by the angular position of revering cam 57 with respect to rotation-control screw 36. The position of revering cam 57 is varied by depressing sector-adjusting pin 80 (after first loosening retaining screw and removing cap 124 to gain finger access to the adjusting pin) while the sprinkler is in operation. When the sector-adjusting pin is depressed, it moves into one of circular sockets 58 in the upper surface of sector-setting ring 53. The sector-setting ring is then forced to rotate with the nozzle-block housing, with ribs 55 on the undersurface of flange 54 clicking or snapping over detents 49 on support legs 48. Wire spring clips 56 flex sufficiently to permit a slight vertical movement of the sector-setting ring as it rotates over the detents.

When a desired limit of rotational travel of the nozzle subassembly is reached, pin is simply released and sector-setting ring 53 assumes a new fixed rotational position with respect to cylindrical sleeve 46. The noule subassembly will then reciprocate between the fixed setting established by rotationcontrol screw 36 and the newly positioned reversing cam 57.

For example, when the nozzle subassembly is moving in a clockwise direction (as viewed from above) and the sector-ad- 60 justing pin is depressed, the degree of rotational travel of the noule subassembly will be shortened. When the nozzles are moving in a counterclockwise direction and the pin is depressed, the extent of rotational motion of the nozzles will be increased. Assuming the sprinkler is initially set for a 180 rotation, the rotation-control screw and reversing cam are angularly separated by 180. If the nozzle subassembly is rotating in a counterclockwise direction and the sector-adjusting pin is depressed and held down for of rotation, the rotational travel of the nozzle subassembly will thereafter be increased by 90 for a new total travel of 270.

correspondingly, if the sector-adjusting pin is depressed when the nozzle subassembly is moving in a clockwise direction, the rotational travel of the sprinkler will be decreased by the amount of angular motion which occurs while the pin is engaged with the sector-setting ring. The limit of rotation established by screw 36 is fixed with respect to the sprinkler housing, and is indicated by the position of pointer rib 300. This fixed" limit can be moved simply by rotating the entire sprinkler on the water supply conduit.

In many sprinkling applications, a full-circle operation may be desired, with the nozzles rotating continuously in one direction. This adjustment is quickly made by removing screws 19 and top plate 18, and removing the sprinkler head from outer housing 11 to gain access to the head of rotationcontrol screw 36 on the undersurface of motor housing 33. Screw 36 is then backed off or retracted three or four turns until its upper end is below the lower tip of lower switching arm 178. The sprinkler is reassembled, and the nozzle subas sembly will rotate clockwise continuously as switch member 169 will remain in the position shown in FIG. with jet 156 driving the impeller in a constant clockwise direction.

The rotary sprinkler is constructed of material selected to be inert to chemical attack by water, or by chemicals such as fertilizers or insecticides applied either above the ground or through the water-supply pipes. Molded fiber-filled plastic parts are used to the greatest extent possible for production economy, strength and resistance to chemical attack. Preferably, the suction nozzle, nozzle block, and motor impeller, bushings, gears, and washers are made of an acetal resin sold under the trademark Delrin. O-ring seals used in the sprinkler are suitably formed from a synthetic-rubber elastomer such as sold under the trademark Buna N. The relatively few metal parts (springs, gear shafts, screws, nozzleblock retaining pins, etc.) are made of stainless steel or cadmium-plated carbon steel. The remainder of the major assemblies of the sprinkler (nozzle-block housing, cap, sectorsetting ring and sleeve, motor housing, top plate and base, outer shell, etc.) are molded from nylon which is reinforced with 30-percent short-hair glass fiber for additional strength.

The gear train and other moving parts of the sprinkler are self-lubricating when exposed to water, and grease or oil is not required. The self-flushing action of the sprinkler will normally keep the sprinkler interior clean and free of debris, but the unit is quickly dismantled should cleaning become necessary. Disassembly involves only removal of cap 124 and top plate 18 so the rotatable sprinkler head can be removed from the outer housing. Clamp ring 186 is then removed, and the entire inner unit is quickly disassembled and cleaned by swirling in water.

The sprinkler of this invention is a highly flexible unit which can be quickly adapted to many different watering applications. For example, in applications where the self-flushing feature is not needed, guide bushing 180 can be shortened and made integral with the floor of the outer shell. Inlet tube 84 is then lengthened a sufficient amount that the tube rides within the stationary bushing over the full range of vertical travel of the head. If it is desired to use a stationary bushing in applications which require flushing of the outer housing each time the sprinkler is cycled, this can still be accomplished by providing suitable bushing or inlet-tube ports for injecting water into the outer housing whenever the head is below a fully elevated position.

In many agricultural applications, the pop-up feature is not needed as the sprinkler is secured to the water-supply conduit above the ground. In such applications, the entire outer housing of the sprinkler can be eliminated if desired, and sprinkler head 12 used as an independent unit. A sprinkler head 190 of this configuration is shown in FIGS. 18 and 19.

Sprinkler head 190 is identical to sprinkler head 12 except for a minor modification to adapt the head for direct mounting on a water-supply conduit. Specifically, head 12 is converted to head 190 simply by removing bushing 35a and installing in its place an inlet adapter 191. The adapter has internal threads 192 to mate with the water-supply conduit fittings, and has an annular wall 193 extending upwardly from its top surface to fit within central opening 35 of motor housing 33 and around inlet tube 84 in the same position occupied by bushing 35a. That is, wall 193 substitutes for bushing 35a in that it permits free rotation of inlet tube 84 with respect to the inner housing.

When adapter 191 has been installed as just described, it is secured in place by reinstalling washer 185 and clamp ring 186 as shown in FIG. 19. The adapter is then rigidly clamped to the sprinkler head, and the head is ready for installation on a water-supply conduit. Subsequent operation of the sprinkler is exactly as already described with reference to sprinkler head 12, with the exception that the unit no longer operates as a pop-up system. Inner housing 14 is clamped to the watersupply pipe and serves as the main outer housing of the spriner. There has been described a rotary sprinkler which is adapted to a variety of different watering applications. The sprinkler has been satisfactorily operated at inlet water pressures ranging from 2 to 150 psi and at delivery rates of A-gallon per minute to -gallons per minute. Range and gallonage variations are readily accomplished by interchangeable nozzle blocks having nozzles with characteristics suited to the particular irrigation requirement. Highly efficient operation is achieved by positioning the motor components outside the main water conduit to eliminate impedances in the primary flow of water to the nozzles. The sprinkler is quickly adjusted for either full or part-circle operation to deliver water only to the area requiring irrigation. The basic sprinkler head is quickly adapted to a variety of different applications, and is equally useful in either a pop-up or vertically stationary configuration.

What is claimed is:

1. A rotary sprinkler, comprising:

a hollow housing with a water inlet;

a nozzle assembly rotatably supported by the housing and having a vacuum nozzle with a water inlet and a vacuum passage, the nozzle assembly defining an unobstructed conduit connected at one end to the housing inlet and at the other end to the vacuum noule inlet for conveying water flowing through the housing inlet to the vacuumnozzle inlet; and

a drive means connected between the housing and nozzle assembly for rotating the nozzle with respect to the housing, the drive means including a rotatable impeller positioned outside the water conduit and a means for delivering water to the impeller, the nozzle vacuum passage being in direct fluid communication with said vacuum nozzle and the interior of said housing to aspirate impeller-driving water out of the housing and through the nozzle after it has passed the impeller.

2. The sprinkler defined in claim 1 in which the nozzle assembly includes a removable nozzle block having a plurality of nozzles in fluid communication with the conduit.

3. In a sprinkler having a water inlet, a rotary head, and a motor with a water-actuated rotary impeller for driving the head, the improvement comprising a vacuum nozzle, an unobstructed conduit interconnecting the vacuum nozzle with the water inlet, said vacuum nozzle having a vacuum passage in direct fluid communication with said vacuum nozzle and connected to the motor downstream of the impeller to enable the nozzle to aspirate water from the motor when water flows therethrough.

4. The sprinler defined in claim 3 in which the motor is disposed outside of the conduit whereby the motor presents substantially no impedance to water flow through the conduit to the nozzle.

5. A rotary sprinkler comprising: a hollow housing with a water inlet;

a nozzle assembly rotatably supported by the housing and having a vacuum nonle with a water inlet and a vacuum passage, the nozzle assembly defining a conduit for conveying water flowing through the housing inlet to the nozzle inlet, the nozzle assembly having a port; and

a water motor disposed within the housing outside the conduit and being connected between the housing and nozzle assembly for rotating the nozzle assembly, the motor having a rotatable impeller and being arranged to receive water from the conduit port to drive the impeller, the nozzle vacuum passage being positioned to aspirate impellerdriving water out of the housing downstream of the impeller whereby water which has passed the impeller is removed and ejected through the vacuum nozzle.

6. The sprinkler defined in claim in which the water motor includes a jet means for controlling the flow of water from the conduit port to the impeller, and a switching means in operative relationship with the jet means for varying the direction of water flow to the impeller so the impeller can be rotated bidirectionally.

7. The sprinkler defined in claim 6 and further comprising a pair of limit stops in the housing and positioned to actuate the switching means at opposite ends of a rotational sector over which the nozzle assembly reciprocates, one of the stops being adjustable with respect to the other stop for adjustment of the extent of the rotational sector.

8. The sprinkler defined in claim 7 in which the housing includes a normally stationary and rotatably supported portion carrying the adjustable stop, and means on the nozzle assembly for temporarily coupling the assembly to the housing portion to rotate the portion and thereby vary the position of the adjustable stop.

9. The sprinkler defined in claim 8 in which one of the stops is adjustable in position to be out of operative relation with the switching means so the jet means can be set to drive the nozzle assembly unidirectionally.

10. The sprinkler defined in claim 5 in which the conduit is a tube extending downwardly from the nozzle assembly to the housing water inlet, and in which the water motor is removably fitted over the tube and keyed thereto to rotate with the nozzle assembly, the water motor having an output gear and the housing defining a ring gear meshed with the output gear.

11. The sprinkler defined in claim 5 in which the nozzle assembly defines a nozzle-block-receiving seat at an outlet end of the conduit, and in which the nozzle assembly further includes a nozzle block removably fitted against the seat and means for releasably securing the seated block to the nozzle assembly.

12. The sprinkler defined in claim 11 in which the nozzle block defines a plurality of nozzles.

13. The sprinkler defined in claim 5 in which the housing comprises an outer stationary housing and an inner housing mounted in the outer housing to be vertically movable between an elevated position when the sprinkler is in use and a retracted position when no water is flowing into the sprinkler, the inner housing carrying the rotatable nozzle assembly.

14. The sprinkler defined in claim 13 in which the inner and outer housings are spaced apart to define a space therebetween, and further comprising means for coupling. the housings together to permit water to flush through the space and out of the sprinkler as the inner housing moves between the retracted and elevated positions, and to terminate water flow through the space when the inner housing reaches the elevated position.

15. The sprinkler defined in claim 13 in which the outer housing has an inlet fitting at its lower end defining the water inlet, and in which the conduit is a tube extending downwardly from the nozzle assembly through the inner housing into fluid communication with the inlet fitting.

16. The sprinkler defined in claim 15 in which the tube includes a tubular bushing at its lower end, the bushing making a slip fit with the outer housing and including a seal for confining water flow from the inlet fitting to the tube when the inner housing is in the elevated position, and for permitting a flushing flow of water to occur between the inner and outer housings when the inner housing is between the elevated position and retracted position.

17. The sprinkler defined in claim 16 in which the nozzle assembly defines a seat at an outlet end of the conduit, the assembly further including a nozzle block having a plurality of nozzles and being removably fitted against the seat, and means for releasably securing the seated block to the noule assembl and in which the water motor is removabl fitted over the tu e and keyed thereto to rotate with the nozz e assembly,

the water motor having an output gear and the inner housing defining a ring gear meshed with the output gear; the water motor further including jet means for controlling water flow from the conduit port to the impeller, and switching means coupled to the jet means for varying the direction of water flow to the impeller so the impeller can be rotated bidirectionally, the housing having a pair of limit stops positioned to actuate the switching means at opposite ends of a rotational sector over which the nozzle assembly reciprocates, one of the stops being adjustable with respect to the other stop for varying the rotational sector.

18. A rotary sprinkler, comprising:

a hollow housing with a water inlet;

a nozzle assembly rotatably supported by the housing and having a vacuum nozzle with a water inlet and a vacuum passage, the noule assembly defining a conduit for conveying water flowing through the housing inlet to the vacuum nozzle inlet; and

a drive means connected between the housing and nozzle assembly for rotating the nozzle with respect to the housing, the drive means including a rotatable impeller and a means for delivering water to the impeller, the nozzle vacuum passage being positioned to aspirate impellerdriving water out of the housing and through the nozzle after it has passed the impeller, the means for delivering water to the impeller includes jet means for bi-directional operation of the impeller, and switching means for controlling the jet means to determine the direction and extent of nozzle rotation.

19. The invention of claim 1 in which the means for delivering water to the impeller includes jet means for bi-directional operation of the impeller, and switching means for controlling the jet means to determine the direction and extent of nozzle rotation. 

1. A rotary sprinkler, comprising: a hollow housing with a water inlet; a nozzle assembly rotatably supported by the housing and having a vacuum nozzle with a water inlet and a vacuum passage, the nozzle assembly defining an unobstructed conduit connected at one end to the housing inlet and at the other end to the vacuum nozzle inlet for conveying water flowing through the housing inlet to the vacuum-nozzle inlet; and a drive means connected between the housing and nozzle assembly for rotating the nozzle with respect to the housing, the drive means including a rotatable impeller positioned outside the water conduit and a means for delivering water to the impeller, the nozzle vacuum passage being in direct fluid communication with said vacuum nozzle and the interior of said housing to aspirate impeller-driving water out of the housing and through the nozzle after it has passed the impeller.
 2. The sprinkler defined in claim 1 in which the nozzle assembly includes a removable nozzle block having a plurality of nozzles in fluid communication with the conduit.
 3. In a sprinkler having a water inlet, a rotary head, and a motor with a water-actuated rotary impeller for driving the head, the improvement comprising a vacuum nozzle, an unobstructed conduit interconnecting the vacuum nozzle with the water inlet, said vacuum nozzle having a vacuum passage in direct fluid communication with said vacuum nozzle and connected to the motor downstream of the impeller to enable the nozzle to aspirate water from the motor when water flows therethrough.
 4. The sprinler defined in claim 3 in which the motor is disposed outside of the conduit whereby the motor presents substantially no impedance to water flow through the conduit to the nozzle.
 5. A rotary sprinkler comprising: a hollow housing with a water inlet; a nozzle assembly rotatably supported by the housing and having a vacuum nozzle with a water inlet and a vacuum passage, the nozzle assembly defining a conduit for conveying water flowing through the housing inlet to the nozzle inlet, the nozzle assembly having a port; and a water motor disposed within the housing outside the conduit and being connected between the housing and nozzle assembly for Rotating the nozzle assembly, the motor having a rotatable impeller and being arranged to receive water from the conduit port to drive the impeller, the nozzle vacuum passage being positioned to aspirate impeller-driving water out of the housing downstream of the impeller whereby water which has passed the impeller is removed and ejected through the vacuum nozzle.
 6. The sprinkler defined in claim 5 in which the water motor includes a jet means for controlling the flow of water from the conduit port to the impeller, and a switching means in operative relationship with the jet means for varying the direction of water flow to the impeller so the impeller can be rotated bi-directionally.
 7. The sprinkler defined in claim 6 and further comprising a pair of limit stops in the housing and positioned to actuate the switching means at opposite ends of a rotational sector over which the nozzle assembly reciprocates, one of the stops being adjustable with respect to the other stop for adjustment of the extent of the rotational sector.
 8. The sprinkler defined in claim 7 in which the housing includes a normally stationary and rotatably supported portion carrying the adjustable stop, and means on the nozzle assembly for temporarily coupling the assembly to the housing portion to rotate the portion and thereby vary the position of the adjustable stop.
 9. The sprinkler defined in claim 8 in which one of the stops is adjustable in position to be out of operative relation with the switching means so the jet means can be set to drive the nozzle assembly unidirectionally.
 10. The sprinkler defined in claim 5 in which the conduit is a tube extending downwardly from the nozzle assembly to the housing water inlet, and in which the water motor is removably fitted over the tube and keyed thereto to rotate with the nozzle assembly, the water motor having an output gear and the housing defining a ring gear meshed with the output gear.
 11. The sprinkler defined in claim 5 in which the nozzle assembly defines a nozzle-block-receiving seat at an outlet end of the conduit, and in which the nozzle assembly further includes a nozzle block removably fitted against the seat and means for releasably securing the seated block to the nozzle assembly.
 12. The sprinkler defined in claim 11 in which the nozzle block defines a plurality of nozzles.
 13. The sprinkler defined in claim 5 in which the housing comprises an outer stationary housing and an inner housing mounted in the outer housing to be vertically movable between an elevated position when the sprinkler is in use and a retracted position when no water is flowing into the sprinkler, the inner housing carrying the rotatable nozzle assembly.
 14. The sprinkler defined in claim 13 in which the inner and outer housings are spaced apart to define a space therebetween, and further comprising means for coupling the housings together to permit water to flush through the space and out of the sprinkler as the inner housing moves between the retracted and elevated positions, and to terminate water flow through the space when the inner housing reaches the elevated position.
 15. The sprinkler defined in claim 13 in which the outer housing has an inlet fitting at its lower end defining the water inlet, and in which the conduit is a tube extending downwardly from the nozzle assembly through the inner housing into fluid communication with the inlet fitting.
 16. The sprinkler defined in claim 15 in which the tube includes a tubular bushing at its lower end, the bushing making a slip fit with the outer housing and including a seal for confining water flow from the inlet fitting to the tube when the inner housing is in the elevated position, and for permitting a flushing flow of water to occur between the inner and outer housings when the inner housing is between the elevated position and retracted position.
 17. The sprinkler defined in claim 16 in which the nozzle assembly defines a seat at an outlet end of the conduit, the assemblY further including a nozzle block having a plurality of nozzles and being removably fitted against the seat, and means for releasably securing the seated block to the nozzle assembly; and in which the water motor is removably fitted over the tube and keyed thereto to rotate with the nozzle assembly, the water motor having an output gear and the inner housing defining a ring gear meshed with the output gear; the water motor further including jet means for controlling water flow from the conduit port to the impeller, and switching means coupled to the jet means for varying the direction of water flow to the impeller so the impeller can be rotated bi-directionally, the housing having a pair of limit stops positioned to actuate the switching means at opposite ends of a rotational sector over which the nozzle assembly reciprocates, one of the stops being adjustable with respect to the other stop for varying the rotational sector.
 18. A rotary sprinkler, comprising: a hollow housing with a water inlet; a nozzle assembly rotatably supported by the housing and having a vacuum nozzle with a water inlet and a vacuum passage, the nozzle assembly defining a conduit for conveying water flowing through the housing inlet to the vacuum nozzle inlet; and a drive means connected between the housing and nozzle assembly for rotating the nozzle with respect to the housing, the drive means including a rotatable impeller and a means for delivering water to the impeller, the nozzle vacuum passage being positioned to aspirate impeller-driving water out of the housing and through the nozzle after it has passed the impeller, the means for delivering water to the impeller includes jet means for bi-directional operation of the impeller, and switching means for controlling the jet means to determine the direction and extent of nozzle rotation.
 19. The invention of claim 1 in which the means for delivering water to the impeller includes jet means for bi-directional operation of the impeller, and switching means for controlling the jet means to determine the direction and extent of nozzle rotation. 